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Blundering Gardener: Whiteflies got the best of me until website remedy came to rescue

By Bonnie Blodgett

Posted:
04/06/2014 12:01:00 AM CDT

As we wait and wait for summer to come, our thoughts turn to the only garden greenery available for our restless pruners to play with: houseplants.

This is an excellent time to focus on houseplants. Those that move outdoors in spring need to be in tiptop shape to make a successful transition.

Plants don't like change. Although dry indoor air isn't ideal, at least your plants are used to it. They are not used to wind, rain and wildly fluctuating temperatures.

As to pests, the whiteflies, spider mites and scale that thrive in your living room won't last long in the company of outdoor predators. But your plants will encounter new nemeses, and healthier plants have better luck fending off foes.

WHITEFLIES WAR

First, check plants thoroughly for signs of pests. I've learned the hard way that infestations I've been able to control but not eliminate tend to worsen as winter drags on. Plants starved for sunlight also lose their fighting spirit.

Whiteflies love my houseplants. Last year, spring came just in time to rescue a 2-year-old tropical honeybush (Melanthus major) whose gorgeous toothy leaves are irresistible to the winged dust specks.

I'm not sure if the bugs were dormant in the soil or if they vanished during summer when the plant lived outside in full sun. Whatever, by mid-March they'd defeated their host plant.

I admit I was their willing accomplice.

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Reluctant to spend $10 on insecticidal soaps that hadn't worked last year, I sprayed the leaves with plain water, drenching the undersides where the larvae live. The whiteflies multiplied.

Next, I pruned the plant, cutting off most of its stems and leaving only fresh leaf growth. This way, I could focus on just a few leaves and keep them squeaky clean. That didn't work, either.

So, I added a dash -- and then a dollop -- of dish soap to bath water. The plant's small and delicate new leaves shrank and then fell off.

Then the whiteflies migrated with breathtaking ease to three large geraniums I had moved from my bedroom to the living room. Silly me, I thought they were immune to whiteflies.

Now I had a dead honeybush, killed by my own hand, and three infested geraniums. A purple-leaved oxalis covered in yellow flowers looked to be next on the whiteflies' hit list.

INCREASED AMMUNITION

Time to find a proven home remedy. I turned to my tried-and-true source: Garden Web.

There I barged into a lively conversation among gardeners dealing with similar problems.

Some other people were there to thank a member of the group for saving their plants from whiteflies with his suggested concoction: a blend of water, vegetable oil and dish soap.

I used peanut oil and followed the directions, being careful to coat the leaves' undersides and repeat the treatment when the bugs reappeared. Within a few days they were gone.

Meanwhile, an email came from a gardening friend who offered another remedy: Mix a solution of 3 cups water, 1 cup rubbing alcohol and 3 teaspoons Ivory dish soap.

If all else fails, use straight rubbing alcohol. (Note: First, test it on some inconspicuous leaves and wait a day.) Repeat every week until pests are gone.

THIS WEEK'S TO-DO LIST

-- As houseplants respond to longer days and more light, they'll appreciate a bit of fertilizer. Start slowly -- a little goes a long way. Never feed a plant that's dormant or fighting off bugs or disease. A sick plant has its hands full without being pushed to grow more leaves.

-- Bone up on the basics you'll need to remember when and if summer ever comes. I'm often asked if woody shrubs can be divided. Most cannot. Perennials, on the other hand, usually benefit. They have fibrous roots, whereas shrubs tend not to grow properly when their roots are sliced apart.

You can start a new shrub or tree from a cutting. This must be taken from a stem, not from the roots. Or you can uproot a plant that's popped up in the soil from an underground runner. Just snip it off the runner and plant it.

-- Many gardeners who are starting seeds under lights for the first time make the same mistake: They begin too early and all at once.

For Zone 4, seed-starting officially begins in late February and ends in mid April. Ideally, all of you vegetable gardeners started your tomatoes, basil and sweet peas in March. There's still time to start melon, cucumber and squash.

Flower gardeners are sowing their morning glories, nasturtiums, sanvitalia, lavatera, nigella and nicotiana. Snapdragons, violas, and possibly salvias, cleome and alyssum are seedlings by now with ageratums and zinnias about to germinate.